Create a strong, long-lasting waterproof roof with our range of Flat Roof GRP products, ideal for garages, extensions and outbuildings. GRP (glass reinforced plastic) roofing systems are a popular choice for flat roofs thanks to their durable, seamless finish and excellent resistance to weathering. Whether you’re installing a new flat roof or repairing an existing one, GRP materials help provide reliable protection against leaks and standing water when installed correctly.
Flat roof GRP is commonly used for garage roofs, dormers, balconies, porches and flat roof extensions, offering a tough surface that performs well year-round. GRP roofing creates a fibreglass layer that forms a strong waterproof barrier, helping extend roof lifespan and reduce maintenance compared to some traditional materials. Using compatible trims, resins and topcoats is essential to achieve a neat edge finish and consistent long-term performance.
For best results, ensure the roof deck is properly prepared, follow correct application steps for resin and matting, and allow full curing time before exposure to heavy weather. Good installation is key to achieving a durable, watertight finish.
Shop online today for flat roof GRP with delivery and collection available.
PRO 25 GRP Topcoat 10kg Dark Grey Fire Retardant is part of a GRP fibreglass roofing system designed for waterproof flat roof construction and repairs.
Builders merchant depots across Leicestershire and Rutland
Three William Hercock depots in Melton Mowbray, Leicester and Oakham supply trade professionals and DIY customers with building materials, timber and landscaping supplies.
Collect from your nearest yard or have it delivered straight to site with HIAB and Moffett offload.
Trade and publicEvery depot is open to trade professionals and DIY customers
Collect or deliveredCollection from any branch or local delivery
HIAB and MoffettCrane and forklift offload straight to site
Rated up to 4.8★ on GoogleFrom 160+ customer reviews across our three depots
Opening hours
The same at all three depots
Monday – Friday7:30am – 5:00pm
Saturday8:00am – 12:00pm
SundayClosed
Bank holiday hours may differ. Please call your branch to check.
What every depot offers
Whichever branch is closest, you get the same service.
Bulk bags and pallet quantitiesOrder by the bag, the bulk bag or the full pallet.
Fast local delivery with HIAB and MoffettCrane and truck-mounted forklift offload, straight to site.
Trade accounts with credit facilitiesCredit terms and trade pricing. Open a trade account
Expert advice from an experienced teamHelp choosing materials and working out quantities.
Reliable stock availabilityKey product ranges kept in stock at every branch.
Open to trade and publicBuilders, contractors and DIY customers all welcome.
Need help with your project?
Our depot teams can help you choose materials and work out quantities.
